Try downloading Firefox from Mozilla, unzip it, and run firefox-bin it from the folder. It's a good idea to have a separate version with your Distro version. https://www.mozilla.org/en-US/firefox/all/#product-desktop-release

To install with Snap look at this. https://vitux.com/4-ways-to-install-mozilla-firefox-in-ubuntu/

It Works in Ubuntu Desktop Edition.

But I need the support to install in Ubuntu Core' 22( Embedded Devices ).

While Running Firefox in UC22 get the error. Error: no DISPLAY environment variable specified.

Hmm there are threads like https://stackoverflow.com/questions/784404/how-can-i-specify-a-display

The minimal system requirements you need to run Firefox is at https://www.mozilla.org/firefox/103.0/system-requirements/

Firefox will not run at all without the following libraries or packages: glibc 2.17 or higher GTK+ 3.14 or higher libstdc++ 4.8.1 or higher X.Org 1.0 or higher (1.7 or higher is recommended) For optimal functionality, we recommend the following libraries or packages: DBus 1.0 or higher GNOME 2.16 or higher libxtst 1.2.3 or higher NetworkManager 0.7 or higher PulseAudio

FFmpeg is also another package to install to have the codecs needed to full HTML5 player support to play video, audio and games.

As per the firefox requirements,

    Firefox will not run at all without the following libraries or packages:
       glibc 2.17 or higher
       GTK+ 3.14 or higher
        libstdc++ 4.8.1 or higher
        X.Org 1.0 or higher (1.7 or higher is recommended)

Ubuntu Core has the mir-kiosk/ ubuntu-frame to display the UI. In the snap store I couldn't find the X.Org package. I can run the wpe-webkit in ubuntu core without any issue.

Would you please confirm, Will Firefox works in ubuntu core? If Yes, Any steps/pre-condition specific to Ubuntu Core 22

Firefox will not run at all without the following libraries or packages:

glibc 2.17 or higher
GTK+ 3.14 or higher
libstdc++ 4.8.1 or higher
X.Org 1.0 or higher (1.7 or higher is recommended)

But Ubuntu Core uses mir-kiosk/ ubuntu frame to display the GUI. I couldn't find the X.Org package in the snap store. Please note, I can launch wpe-webkit in Ubuntu Core 22. Please confirm, will firefox works in ubuntu core?

As per the Firefox requirements, It needs X.Org 1.0 or higher (1.7 or higher is recommended)

But Ubuntu Core has mir-kiosk / ubuntu frame to display the UI. I able to run wpe-webkit in ubuntu core 22. As Ubuntu Core supports only snap. But I couldn't find snap package X.org Will Firefox run in Ubuntu Core?

Let me know the steps/ pre-condition to run the firefox in ubuntu Core 22